A gate driver on array (GOA) generates a scan driver circuit on an existing array substrate of a thin film transistor liquid crystal display (TFT-LCD) in order to implement a driving method which progressively scans for scan lines. A structural diagram of an existing scan driving circuit is illustrated in FIG. 1, and the scan driving circuit 10 includes a pull-up control module 101, a pull-up module 102, a down-stream module 103, a pull-down module 104, a bootstrap capacitor 105, and a pull-down maintaining module 106.
The scan driving circuit generally uses an N-Metal-Oxide-Semiconductor (NMOS) type transistor. However, for the production of the NMOS transistor, the production cost of a photomask which is used in a photolithography process is higher. Moreover, the overall circuit structure of the scan driving circuit is more complex so as to consume more energy.
As a result, it is necessary to provide a scan driving circuit to solve the problem existing in the conventional technologies.